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Diffstat (limited to 'drivers/media/dvb/ttpci/ttpci-eeprom.c')
-rw-r--r--drivers/media/dvb/ttpci/ttpci-eeprom.c146
1 files changed, 146 insertions, 0 deletions
diff --git a/drivers/media/dvb/ttpci/ttpci-eeprom.c b/drivers/media/dvb/ttpci/ttpci-eeprom.c
new file mode 100644
index 000000000000..e9a8457b0727
--- /dev/null
+++ b/drivers/media/dvb/ttpci/ttpci-eeprom.c
@@ -0,0 +1,146 @@
1/*
2 Retrieve encoded MAC address from 24C16 serial 2-wire EEPROM,
3 decode it and store it in the associated adapter struct for
4 use by dvb_net.c
5
6 This card appear to have the 24C16 write protect held to ground,
7 thus permitting normal read/write operation. Theoretically it
8 would be possible to write routines to burn a different (encoded)
9 MAC address into the EEPROM.
10
11 Robert Schlabbach GMX
12 Michael Glaum KVH Industries
13 Holger Waechtler Convergence
14
15 Copyright (C) 2002-2003 Ralph Metzler <rjkm@metzlerbros.de>
16 Metzler Brothers Systementwicklung GbR
17
18 This program is free software; you can redistribute it and/or modify
19 it under the terms of the GNU General Public License as published by
20 the Free Software Foundation; either version 2 of the License, or
21 (at your option) any later version.
22
23 This program is distributed in the hope that it will be useful,
24 but WITHOUT ANY WARRANTY; without even the implied warranty of
25 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
26 GNU General Public License for more details.
27
28 You should have received a copy of the GNU General Public License
29 along with this program; if not, write to the Free Software
30 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
31
32*/
33
34#include <asm/errno.h>
35#include <linux/init.h>
36#include <linux/module.h>
37#include <linux/string.h>
38#include <linux/i2c.h>
39
40
41#if 1
42#define dprintk(x...) do { printk(x); } while (0)
43#else
44#define dprintk(x...) do { } while (0)
45#endif
46
47
48static int check_mac_tt(u8 *buf)
49{
50 int i;
51 u16 tmp = 0xffff;
52
53 for (i = 0; i < 8; i++) {
54 tmp = (tmp << 8) | ((tmp >> 8) ^ buf[i]);
55 tmp ^= (tmp >> 4) & 0x0f;
56 tmp ^= (tmp << 12) ^ ((tmp & 0xff) << 5);
57 }
58 tmp ^= 0xffff;
59 return (((tmp >> 8) ^ buf[8]) | ((tmp & 0xff) ^ buf[9]));
60}
61
62static int getmac_tt(u8 * decodedMAC, u8 * encodedMAC)
63{
64 u8 xor[20] = { 0x72, 0x23, 0x68, 0x19, 0x5c, 0xa8, 0x71, 0x2c,
65 0x54, 0xd3, 0x7b, 0xf1, 0x9E, 0x23, 0x16, 0xf6,
66 0x1d, 0x36, 0x64, 0x78};
67 u8 data[20];
68 int i;
69
70 /* In case there is a sig check failure have the orig contents available */
71 memcpy(data, encodedMAC, 20);
72
73 for (i = 0; i < 20; i++)
74 data[i] ^= xor[i];
75 for (i = 0; i < 10; i++)
76 data[i] = ((data[2 * i + 1] << 8) | data[2 * i])
77 >> ((data[2 * i + 1] >> 6) & 3);
78
79 if (check_mac_tt(data))
80 return -ENODEV;
81
82 decodedMAC[0] = data[2]; decodedMAC[1] = data[1]; decodedMAC[2] = data[0];
83 decodedMAC[3] = data[6]; decodedMAC[4] = data[5]; decodedMAC[5] = data[4];
84 return 0;
85}
86
87static int ttpci_eeprom_read_encodedMAC(struct i2c_adapter *adapter, u8 * encodedMAC)
88{
89 int ret;
90 u8 b0[] = { 0xcc };
91
92 struct i2c_msg msg[] = {
93 { .addr = 0x50, .flags = 0, .buf = b0, .len = 1 },
94 { .addr = 0x50, .flags = I2C_M_RD, .buf = encodedMAC, .len = 20 }
95 };
96
97 /* dprintk("%s\n", __FUNCTION__); */
98
99 ret = i2c_transfer(adapter, msg, 2);
100
101 if (ret != 2) /* Assume EEPROM isn't there */
102 return (-ENODEV);
103
104 return 0;
105}
106
107
108int ttpci_eeprom_parse_mac(struct i2c_adapter *adapter, u8 *proposed_mac)
109{
110 int ret, i;
111 u8 encodedMAC[20];
112 u8 decodedMAC[6];
113
114 ret = ttpci_eeprom_read_encodedMAC(adapter, encodedMAC);
115
116 if (ret != 0) { /* Will only be -ENODEV */
117 dprintk("Couldn't read from EEPROM: not there?\n");
118 memset(proposed_mac, 0, 6);
119 return ret;
120 }
121
122 ret = getmac_tt(decodedMAC, encodedMAC);
123 if( ret != 0 ) {
124 dprintk("adapter failed MAC signature check\n");
125 dprintk("encoded MAC from EEPROM was " );
126 for(i=0; i<19; i++) {
127 dprintk( "%.2x:", encodedMAC[i]);
128 }
129 dprintk("%.2x\n", encodedMAC[19]);
130 memset(proposed_mac, 0, 6);
131 return ret;
132 }
133
134 memcpy(proposed_mac, decodedMAC, 6);
135 dprintk("adapter has MAC addr = %.2x:%.2x:%.2x:%.2x:%.2x:%.2x\n",
136 decodedMAC[0], decodedMAC[1], decodedMAC[2],
137 decodedMAC[3], decodedMAC[4], decodedMAC[5]);
138 return 0;
139}
140
141EXPORT_SYMBOL(ttpci_eeprom_parse_mac);
142
143MODULE_LICENSE("GPL");
144MODULE_AUTHOR("Ralph Metzler, Marcus Metzler, others");
145MODULE_DESCRIPTION("Decode dvb_net MAC address from EEPROM of PCI DVB cards "
146 "made by Siemens, Technotrend, Hauppauge");